Bunk bed



FIG. 1 is a perspective view of a bunk bed showing my new design;

FIG. 2 is a left end elevational view thereof;

FIG. 3 is a right end elevational view thereof;

FIG. 4 is a front elevational view thereof, the back being a mirror image thereof;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a bottom plan view thereof.

The phantom representations of mattresses in the drawings are merely for the purpose of illustrating the environment in which the invention is used, and do not form part of the new design. 

The ornamental design for a bunk bed, as shown and described. 